This proposal seeks to continue current studies in the synthesis of cytotoxic and antineoplastic natural products. New chemical methods are to be developed along with the preparation of substrates for biological evaluation. The completion of the synthesis of eriolanin and eriolangin is planned. Methods developed for the synthesis of aromatin will be applied to fastigilin-type pseudoguaianolides. Experience gained with the Cope-Claisen rearrangement will be utilized in the synthesis of the cytotoxic substance, quadrone. Finally, studies will be started which will be applicable to the synthesis of the antitumor substance, bruceantin.